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Lean Six Sigam

There are multiple hypothesis tests available in Minitab and should be utilized as per data type and the objective.

Let’s take an example of one sample t-test.

One sample t-test

One sample t-test is used to compare population mean with a defined value using sample data.

The test uses sample standard deviation to calculate population standard deviation. If there is a large difference between the sample mean and the specified test mean (given value), then the test concludes that it is highly unlikely that population means will be anywhere near test mean.

Assumptions

1. Sample data follows normal distribution

2. Sample data is random

Analysis in Minitab

Let’s assume sample data of average handling time:

To validate if the goal of reducing population mean to 4 minutes is significant, we can use one-sample t-test.

H0: Hypothesized Mean (4 min) = Population Mean (µ)

H1: Hypothesized Mean > Population Mean (µ)

Step 1: Check if data follows normal distribution to ensure we can use t-test.

To check do to Stat -> Basic Statistics -> Graphical Summary

If p-value is greater than 0.05, that means data follows the normal distribution.

NEBOSH stands for “National Examination Board in Occupational Health and Safety. It is UK based independent examination board providing certification in health, Safety, and Environment. This course provides broader knowledge on risk management, health, and safety.

IOSH stands for “Institution of Occupational Safety and Health.” It’s professional health and safety membership forum, conducts training for managers, supervisor. This training will help managers to take appropriate action to handle practical situations.

Both NEBOSH and IOSH are relevant if you are looking for long term career in health and safety.

Now, let’s look at Six Sigma relevance.

Six Sigma is a data-driven methodology first introduced in the 1970s. Six Sigma is based on data analysis, hence helps in reducing risk which one of the many reasons that Six Sigma is still preferred over other improvement methodologies. The objective is to remove defects at the source and bring down performance to ‘six sigma’ level i.e. 3.4 defects for every one million opportunities. Continuous effort is made to achieve stable and predictable process.

Jack Welch made it the center of business strategy at General Electrical. In today’s competitive world, Six Sigma has widely accepted as a philosophy for growth across different sectors.

Six Sigma applies to all departments and industries. It has a very broad scope. So, professionals at all level are taking this course to improve day-to-day business and hence their performance.

Long answer short, my recommendation is you should go for Six Sigma course.

‘Throughput’ is the number of items produced by a process in a given period of time. And ‘Cycle time’ is the average time required to produced one item by a process.

So if for Process A, cycle time is 10 mins per item.

Throughput of the process will be 6 items per hour.

Lead time is the time required to deliver final product to the client, i.e. time lag between initiation and completion of the request.

Assume, for A Process A, a request was raised on 20-Mar and product delivered to client on 22-Mar, the lead time is 2 days while the cycle time is only 10 mins, which means for rest of the time the request Is actually waiting in the queue for some reason/s. This gives you an opportunity for process improvement.

Another concept worth understanding is Takt time.

Takt time is the rate at which process should run in order to meet customer demand.

For example, on a particular day for Process A, the demand is 100 items.

So with the current cycle time of 10 mins, you won’t be able to achieve demand. Hence the cycle time should always be less than takt time. Now, you can run another project to reduce process cycle time to 9.6 mins per item.

Companies across all sectors are giving a lot of importance to process excellence in the current world. I have seen many companies promoting Lean Six Sigma training program. They also run in-house process excellence training programs. Sometimes, it’s part of manager’s KRA to get x% of resources trained on basic process excellence methodology. And some companies also expect manager’s to have knowledge of Lean Six Sigma to get promoted to the next level.

After certification, you can get into the core process excellence role, which will involve identifying process improvement opportunities, competency building, helping business operations to run as per service level agreement, etc. In this role, you won’t be a part of any primary service teams but will be aligned with them to achieve process efficiency more like a third party character. Depending on your experience, you can get into a particular hierarchical level.

Another option is to stay in main business line i.e. as a part of some operations team and use process excellence knowledge to get that extra bonus points. Kano model developed in 1980, still holds true for customer satisfaction. There are basic needs (must be’s), performance needs (leading to satisfaction if fulfilled and dissatisfaction if not), and delighters. Lean Six Sigma certification will help you identify and achieve those delighters.

Value stream mapping is a lean enterprise technique used to analyze and improve the flow of information/material through series of value-adding events taking product/services from supplier to the customer

Value stream map (VSM) gives a visual depiction of the end to end process flow. Unlike standard process flow, VSM will not only have all process step in sequential order of production but also will show material and information flow and multiple data points like cycle time, waiting time, defect rate at each stage, inventory at each stage will also be depicted. It will be the one-page Bible for the leaders to identify improvement areas, recommend solutions and analyze the impact of a solution on other departments as well.

The primary objective of Value stream map is to identify waste and improve material/information flow. There is no standard way of how to use value stream map but at large most of the companies follow below mentioned general steps for creating value stream map:

NVA: Process step which is not adding value. The objective is to minimize essential non-value added time as much as possible.

Eight types of wastes can be identified in process: Transport(movement of material/product), Inventory, Motion (movement of people), Waiting (people/material waiting in queue), Overproduction (producing more than or before required), Over-processing (processing more than required), Defect (products not matching customer expectations)

Step 4: Identify improvement opportunities

Kaizen is the practice of continuous improvement. The improvement opportunities are depicted in VSM as Kaizen-burst. Examples of improvement opportunities are Non-Value Added activities / Waste, high change over time/ cycle time, multiple/unnecessary communication, duplicate activities etc

Step 5: To be Value Stream Mapping

Multiple Lean tools can be used to recommend improvement opportunities:

1. 5S = Sort, Set in Order, Shine, Standardize, Sustain

2. Standard work = Documenting most efficient way for doing work

3. Jidoka = Automation that will stop as soon as error occur

4. Visual Andon = Visual signal that shows the status of a process.

5. Poka Yoke = Mistake proofing to prevent or detect errors

6. Kanban = Signal cards used to denote product details

To-be Value stream mapping should be drawn assuming all recommendations are implemented. An implementation plan should be finalizes